Balser is pushing for legislation that would train prison staff to deal with mentally ill inmates, and provide live-in treatment units instead of solitary confinement for prisoners who need to be isolated from the general prison population.

"It's clearly an issue of treating people humanely, but beyond that there's an issue of cost effectiveness and public safety," said Balser, who heads the Legislature's Joint Mental Health and Substance Abuse Committee. "We're spending a lot of money on these folks because they cut themselves, they hurt each other and we're sending them to hospitals."

Balser believes her bill would help the approximately 25 percent of prisoners who suffer from mental illnesses and have a heightened risk of suicide get help instead of punishment when they act out.

The legislation requires that all inmates be mentally evaluated within 24 hours of entering solitary confinement to determine if they should be moved to treatment units, which Balser described as psychiatric wards within a prison.

Between 200 and 300 of the 11,000 state prison inmates have severe enough mental illnesses to be placed in the special units, said Leslie Walker, executive director of Massachusetts Correctional Legal Services.

If the state had better treatment programs, Daniel Davares Jr., who killed a young couple in Washington after being released from prison last month, might have had the tools to deal with his bipolar disorder, Walker said.

"There are more Danny Davareses in there than I care to count," said Walker, who believes mentally ill prisoners should be considered patients first and inmates second.

With 90 percent of prisoners eventually re-entering society, Balser worries that the strain of solitary confinement makes many prisoners more dangerous than before their incarceration.

Gov. Deval Patrick's Executive Office of Public Safety is currently installing a $1 million residential treatment unit at Souza-Baranowski Correctional Center in Shirley, the first in a state maximum security facility.

The Legislature cut $13 million from the Department of Correction's budget request last year, money that could have helped build units at other prisons, said Terrel Harris, Executive Office of Public Safety spokesman.

"The biggest challenge is not a lack of willingness in the House ... but we're facing a $1 billion deficit so everything has to be looked at in terms of cost," Balser said.

While she would like the Legislature to partner with Patrick on her bill, Balser said it may be quicker for the governor to implement a similar policy without legislative approval.

Balser said she hopes to meet with recently appointed Department of Correction Commissioner Harold Clarke, and is optimistic that his progressive reputation bodes well for her proposal.